Part B: Project Planning & Control
The project management aspect starts with defining the resource allocation, timelines and budgets for several developmental aspects of the Airport PDA project. It has the following project activity parameters.
AOA/AON, Gantt charts and Critical Path Assessment (Q5/Q6)
These duration estimates are expressed as: a (optimistic), m (mostly likely) and b (pessimistic) parameters in each project activity or milestone. Once their values have been estimated based on experience and educated guess, the expected time of completion can be computed using PERT formula (a + 4m + b) / 6 which yields the values reflected on the 6th column of Table 7. Computing for the early start/finish and late start/finish as well as the slack times yield the columns thereafter (7th to 11th). Based on the early start/finish and late start/finish, the critical activities with zero float or slack times emerged to show the critical path. The arrow node charts on Table 8 and Table 9 below illustrate this.
Table 7: Project activities and duration
Table 8: Project activities in AOA
Table 9: Project activity on AON Chart
A slack time or a float of zero defines a critical activity (Meredith) which must be completed as scheduled or the next task cannot start and project delays become a certainly unless the succeeding task can be finished ahead of schedule. Creating the Gantt chart as illustrated in Table 10 clearly indicates which tasks have slack times and which does not. The critical path become obvious and in cases like these, determining the critical path is fairly obvious and there’s no need to use the CPM,
Based on the expected duration time computed form the Table 7, the Project Gantt chart is constructed below with initial critical path presented. The project is expected to be completed in 4.5 months based on expected time of completion. Of course, very few projects, if at all, ever get done on schedule or as planned mostly due to several factors like, unexpected supervening events beyond the control of the project manager, accidental errors along the way, change in corporate priorities, changes in the project activities due to changes in suppliers, project team member turnovers, or inability to get the need resources in time.
Table 10: Project Gantt Chart
Scheduling Optimization Option
A great deal of time and effort often goes in planning a project in an the hope of arriving at the optimum schedule of activities mapped out to match time-sensitive resource allocation and to bring the project to its conclusion at the least cost and at the earliest possible time (Meredith). For sure, there are appropriate ways to schedule activities such as trial and error, Heuristic prioritization and optimized modeling using linear programming. For this project, a simple Heuristic prioritization using minimum slack activities as having the highest priority can be used to optimum effect. The minimum slack rule is often the most preferred scheduling method. This is constrained and something compromised by the availability of resources when needed and any lack thereof can restrict how far the project manager can manipulate the schedule without have any impact to the overall project deliverables and completion date.
From Table 11, the manpower resources are fairly spread homogenously throughout the project duration. Without any peaks or troughs, no resource smoothing is necessary as this would be just a waste of time in a project like these.
Table 11: Labour resource spread over the project duration
In getting the critical path variability, Table 11 shows the variance total among critical activities as 2 days and the standard deviation is its square root or 1.41 weeks. If management can only tolerate a 2% probability of not meeting the deadline, then multiplying 1.41 weeks x 2.054 (z-score found in a probability distribution table) yields 2.02 or 2 weeks. In short, management can only accept a 2-week delay form a planned 20=week project timeline.
Determining the probability that the project task will meet deadlines must be approached with a grain of salt as these are mostly the best guess estimates meant to boost confidence of the project sponsors and approving bodies. It’s a fact of life that the most well-planned projects rarely even fall within the target deadlines. But having the information gives projecti managers a better handles on the project.
Reducing the Project Duration By Two Weeks (Q8)
A sudden urgency may prompt the project manager to reduce the project timeline by two weeks. A simple tabulation of the crash and normal duration and their corresponding associated costs per activity are shown on Table 13.
Table 13: Cost Slope of activities
Critical activities B, E, F, and L can be crashed. The rule of thumb is to reduce the duration of a critical task with the least cost slope, Reducing B by two weeks will move the project two weeks forward but will cost £1,400. Another option is to crash E and F one week each which will cost £1,100 for an overall two-week reduction. The latters makes for a cheaper option.
Project Performance as of the half point(Q9)
On the 10th week or at the project’s half time mark, the summary of actual project expenses compared with budget allocation for each project activity is tabulated and it is plain the that the project is slightly behind schedule. It should already hit 51.7% complete but is running at 48% which is not entirely out of hand. The project enjoys a negative cost variance of 0.4% which means that out of a planned budget of £77,000 so far, it went overboard by a measly £300.
Table 14: Actual and budget cost Summary for each activity and actual
On the other hand, a negative completion variance of 14.5% as of the 10th week indicates that its completion level is off by that amount. At the time the report was made, the project should be 51.7% complete, but is hitting only 48.3%. And when it should be 88.6% complete for the 10th week, it is only hitting 75.7%. Despite overshooting the budget by just a small amount, it has failed to complete the project in the time allotted and unless subsequent schedules are completed earlier, is certain to result in failure to meet the project’s overall deadline.
Optimizing Resource Mix (Q10)
The project manager needs to minimize the cost of Rouserces U and V used in a certain project task. The details are provided in tableseeks to minimize the total cost of a certain activity related to this
Table 15: Constraints for resources U and V
| Resource | Cost | (y) | y+2x | y-x |
| U (y) | £400 | At least 2.5 resource-hours | Not to exceed 7.45 resource -hours | Not to exceed 1.75 resource-hours |
| V (x) | £900 | | | |
Given the X and Y conditions in the table, a Cartesian graph is made and the Y – X = 1.75 and Y + 2X – 7.45 equations are plotted. Given the minimum and maximum values, the result is a set of values falling within a triangular area as illustrated in the graph. Upper limit for Resource U is 3.5 RH and lower limit is 2.5 RH. Upper limit for Resource V is 2.5 RH and lower limit is around 0.75 RH. These values and their corresponding optimal costs are tabulated below.
Table 16: Optimal resource costs
Resource | Cost | Upper Limit | Cost | Lower Limit | Cost |
U (y) | £400 | 2.5 | £1,000 | 0.75 | £300 |
V (x) | £900 | 3.5 | £3,150 | 2.5 | £2,250 |
Conclusion
While the use of PERT/CPM provides project managers a set of tools, that enable them to check on the viability of a project’s timeline, they are rarely used in real world projects as the time and effort to gather all the data needed in the computations are better spent on getting the project on the road (Coster). Indeed, observations have revealed that whether you use them or go for a trial and error approach, it is rare that a complex project can meet the target deadlines and within budget. But having said that, the tools are now better harnessed with project management software that use them as part of its algorithms and can benefit management in better adjusting schedules within available resources in part rather than in totality.
Project managers in charge of the company’s Airport PDA project has 12-18 months to implement their new product offering and get the most cost-effective market to win local airports for starters. This can be greatly reduced by identifying prospective partners in the supply chain to ensure the company does not re-invent wheel and get the best deal in any business partnership. Three areas and operationally critical, getting the vehicle-mounted PC hardware, the program to interface with airline and airport systems, and the telecommunications infrastructure in place at the airport. Having the business alliance in place at this time is the first step and the best way to get the project off the ground and achieve the shortest implementation time.
